سیدرضا حسن بیگی

Leafy vegetable harvesting machines are made with the aim of improving the efficiency of harvesting, reducing the damage to the plant, reducing the need for manpower and also reducing contamination. In current research, a cutting system for leafy vegetable harvesting machine was designed and constructed. The system was tested on watercress, spinach and basil. The machine consists of a band saw blade that is placed on two pulleys. The pulleys are rotated by an electric motor powered by three-phase electricity. Driving pulley was connected to the motor by a shaft and a coupling. Two ball bearing were used to prevent angular deflection of the shaft. The driven pulley is also attached to the U-shaped frame by a shaft and ball bearing. The bearing connected to the movable pulley is responsible for adjusting the required tension of the saw blade. A screw and two nuts were used to provide the blade tension by screwing. The assembly is mounted on an inverted U-shaped metal frame, which is attached to the main chassis of the machine. The wheels are connected to the main chassis by a height adjustment mechanism. The constructed system was tested at blade linear velocities of 3.7T 5 and 6.3 m/s and forward speed levels of 1, 1.5 and 2 km/h. Experiments were designed by Minitab 2018 software and 13 experiments were designed for each of the three plants using the central composite design method. According to the results obtained in this study, the optimal blade linear velocity was 6.3 m/s and the forward speed in the range of 1.7 to 2 km/h. Also, the stems were cut by this machine without crushing and caused the least damage to the plants.

Fault diagnosis of rotary machines plays an essential role in reliability and safety of new industrial systems. Gears are considered as a vital part of the components of industrial machines, so that the defects of these components cause irreparable damages in industrial processes. Nowadays, many research workers conduct studies on the diagnosis of gear faults using data analysis. In this research, to acquire acoustic data from a sample gearbox, a system was fabricated and developed. Then, some common faults in the gearbox teeth were created artificially. In this research, cepstrum analysis method was used in order to detect the harmonics of gear mesh frequency and the family of sidebands created. In the primary investigation, the harmonics related to the gearbox shaft were identified with the cepstrum analysis method in the interval of 0 to 0.25 seconds. Then, in order to detect the faults of the gear, by analyzing in the interval of 0 to 0.0002 seconds, the faults related to the tooth were clearly visible and tracked. According to this research results by observing increase in amplitude of the first and fifth rahmonics, it is possible to detect faults such as broken and worn teeth of gears. The obtained results show the effectiveness of the presented method to diagnose the fault in the gearbox and prevent unexpected costs.

Pressure fluctuations during fuel injection are one of the factors that negative effect on performance of diesel engine. These fluctuations are caused by the rapid opening and closing of the nozzles and the creation of pressure waves in the fuel rail. One way to control these pressure fluctuations is to change the injector design and use an accumulator in the injector. This study is performed to investigate the effect of adding accumulator on the injector to control pressure waves in the common rail fuel injection system of diesel engines. As the simulation results show, at injection pressure of 1000 bar and energizing time of 0.8 milliseconds, in the case of no accumulator, the maximum pressure fluctuation in the fuel rail is 1046 bar and the minimum pressure is 891 bar. By adding an accumulator with a volume of 4 cm3, the maximum pressure continued to decrease and reached 1023 bar, and the minimum pressure of the fuel rail increased by 17 bar, 943 bar. These changes are also noticeable in other pressures and energizing times, so the best accumulator that has the most impact on reducing pressure fluctuations is the accumulator with a volume of 4 cm3.

In this study, acoustic and vibration response methods were used to non-destructively estimate the firmness of apples. Gala apples were stored at 0 and 20 ° C for 9 and 6 weeks and were tested for acoustic response every week during storage. During the test, the samples were placed on a special device designed and made for this test and stimulated with a gentle tap. Impact sound and vibration were received by the microphone and accelerometer and transmitted as analog signals to the computer sound card and then converted to digital signals. Digital signals were converted from time domain to frequency domain by Fourier transform in MATLAB software. The dominant frequencies of the sound and vibration signals were extracted and the firmness indices were obtained from special equations. The results of acoustic and vibration tests were compared with the results of puncture test. The correlation coefficient between puncture firmness and firmness index was more than 0.92, which was significant at the probability level of 1%. Also, the dominant acoustic and vibrational frequencies and mass of the samples were used as three features as single, binary and ternary using artificial neural network to estimate the shelf life of apples. The shelflife was estimated at one, two and three week intervals and the results of fusion of binary and ternary in different modes increased from 9% to 30% the accuracy of classification of individual features.

Densification of biomass materials such as briquette improves the management properties of materials for transportation, storage, and so on. This study aimed to determine the optimal conditions of the briquette production process using a hydraulic press from the combination of bagasse and walnut shell using response surface methodology. The effects of independent variables including bagasse particle size (PS), process temperature (PT), bagasse moisture content (MC), and the composition ratio percentage of the walnut shell to bagasse (CR) were evaluated at three levels on the response variables of the density and tensile strength. The calorific value of the briquette was determined through validated linear and nonlinear equations of the high heat value using the proximate analysis of volatiles, fixed carbon, and ash. The results showed that by decreasing the moisture content of bagasse particles, the density and tensile strength of the briquette increased. Adding walnut shell particles to the briquette produced with the size of fine particles reduces tensile strength. The briquette production significantly reduced the percentage of volatile materials relative to their biomass and increased the percentage of fixed carbon. The calorific value of the raw material sample relative to the briquette produced increased from 16 to 22 MJ/kg. The optimal values of the density and tensile strength of briquettes were equal to 867.847 kg/m3 and 1.356 MPa, respectively at the CR of 5%, PS less than 1.18 mm, MC content of 7%, and PT of 360 °C. At this condition, the calorific value of 22 MJ/kg was obtained.

In this paper, modeling and control of a robotic carrier for the cleaning system of solar farms are presented. Since solar panels are placed in natural environments, there is always a problem of dust accumulation on the panels, which results in absorbed energy reduction. Hence, robotic cleaners can be used for solar panels. For relocation of the cleaning robot between solar panel rows, an automated carrier mechanism is required. Hence, a robotic system for cleaner displacement is introduced, and its dynamics modeling and control are presented. The robot kinetics and kinematics models have been derived and validated by ADAMS software. Hence, kinetics and kinematics model-based controllers are introduced for robot motion control. Using the kinetics model, a computed torque method controller is designed and simulated. For less computational effort, a transposed Jacobian controller is designed, using the kinematics model. Finally, to increase control performance, an modified transposed Jacobian controller is also designed. The desired trajectory is designed for the robot. Finally, for software verification and analysis, the controllers are simulated, using co-simulation of MATLAB Simulink and ADAMS model. The simulation results show the satisfactory performance of the controllers and can be used for further design analysis of the prototype.

Bread waste is the common part of food biomass in the world. The aim of this study was to investigate the effects of saccharification time and also substrate concentration on the amount of glucose as well as bioethanol obtained from bread wastes folowing hydrolysis processing. The bread wastes were crushed to small parts and then mixed with water at ratio of 10-15 (w/v%). Alpha-amylase and glucoamylase enzymes were used for liquefaction and saccharification, respectively. The effects of saccharification time and substrate loading parameters on the amount of glucose were investigated by using response surface methodology (central composite design) with Design Expert software. The glucose-derived from hydrolysis processing was measured by glucose kit. Aflatoxin contents of the bread wastes (as control sample) and optimum sample obtained from the hydrolysis processing (sample with the maximum glucose) were measured. Fermentation processing was carried out by using Saccharomyces cerevisiae yeast. The results showed that the highest amount of glucose (100.21 g/l) in enzymatic hydrolysis was obtained at the saccharification time of 48 h and substrate loading of 150 g/l. The hydrolysis processing at the higher concentrations and longer duration, due to high viscosity and adhesion, reduced the concentration of glucose, so high concentration did not have any favorable effect on the hydrolysis processing. The hydrolysis processing reduced Aflatoxin B1 and B2 at a ratio of 76% and 16%, respectively. The greatest amount of bio-ethanol in the fermentation phase (45.35 g/l) was obtained at 36 hours with efficiency of 88.7%. It could be related to the consumption of glucose produced in the hydrolysis phase due to proper growth of the cell mass during fermentation phase in this duration. The recommended time for the fermentation processing is 36 hours.

The combustion processes, engine performance, fuel consumption, exhaust-gas composition, and combustion noise in the diesel engine are closely linked to appropriate mixture of air-fuel in combustion chamber. The fuel-injection parameters such as injection start point, discharge rate curve, injection time and injection pressure are defined by the quality of the mixture formation. The numerical modeling is the common method of investigation of fuel pressure and its effects on the injection quantity in the fuel system. In this study, one-dimensional common rail fuel injection system was simulated in AMEsim software. The simulation results illustrated that the higher injection pressure can lead to higher pressure fluctuations. Because of compressibility of fuel, its density increased with the increase of pressure, resulting in faster propagation of distribution in the whole high pressure tubes. The delay in closing the throat and moving the needle downwards, moreover, led to the difference between Injection time and solenoid stimulation in different pressures. Closing delay, also, increased with increasing pressure.

The use of diesel engines day by day increased because of their low fuel consumption and high performances. Common rail diesel engines with electronic fuel injection can accurately meter the fuel injection quantity and fuel injection pressure. Injection spray pressures in diesel engines play an important role for engine performance and emissions obtaining treatment of combustion. In this paper, effects of fuel injection pressure and spray cone angle on the exhaust emissions of a national diesel engine have been numerically investigated using a model verified by experimental data. In this study, four fuel injection pressures of 1000, 1400, 1600 and 1800 bar and three spray cone angle of 15, 25 and 35 degrees at 1400 bar injection pressure were investigated. The simulation results showed that by increasing the fuel injection pressure, the maximum pressure inside the combustion chamber increased from 144 to 162 bar and the temperature inside the combustion chamber increased by 8.2% and changed from 1607 to 1740 K. Subsequently, the amount of NOx produced also increased. But the amount of soot decreases with increasing fuel injection pressure due to better mixing of fuel and air. Changing the spray cone angle from 15 ° to 35 ° decreased the pressure inside the combustion chamber from 157 to 152 bar. One of the reasons for this decrease was the impact of fuel droplets against the walls of the combustion chamber at higher spray cone angles, this causes the fuel to not completely vaporize. An increase in the temperature of the combustion chamber was observed at a cone angle of 15 ° C relative to 35 ° C from 1654 to 1718 ° C. An increase in the temperature of the combustion chamber was observed at spray cone angle of 15 ° relative to 35 ° from 1654 to 1718 K.

In-spite of large amounts production of bread waste annually, this waste is not suitable for food and animal feed applications due to aflatoxin contamination. In this study, bio-ethanol production from bread waste by Saccharomyces cerevisiae was investigated using acidic hydrolysis method. The acidic hydrolysis was performed by an autoclave apparatus. The effect of acidic solution concentration and time on amount of glucose was investigated. The experiments were carried out at loading of 160 g/l. Reduction of aflatoxin was measured for the sample with the greatest yield in acid hydrolysis. The sample obtained from hydrolysis was used for the production of bio-ethanol using Saccharomyces cerevisiae. The results showed that the effect of concentration of acid and time was significant at 1% level on the amount of glucose. Hydrolysis liberated the greatest amount of carbohydrate (80.64 g/l glucose) at the acidic solution concentration of 1% and time of 20 minutes. Also, acidic hydrolysis reduced aflatoxin B1 and B2 by 100% and 20.70%, respectively. The greatest percentage of bio-ethanol production in the fermentation phase of hydrolysis samples was 4.7 (v / v%).

Using the  acoustic response analysis is one of the non-destructive methods to determine the texture quality and firmness of fruits such as apples, pears, peaches and other crops such as watermelon, melon and cantaloupe. In this study, a portable device designed and fabricated which has a pendulum to apply the computer-controlled impact to the sample, to investigate the non-destructive quality of apple fruit based on firmness. When pendulum hits the sample, both the acoustic and vibration sensors simultaneously receive the impact signals and after transferring to the computer, the fast Fourier transform will calculate their dominant frequency. The sample firmness index is calculated from the dominant frequency and weight. The dominant frequencies and firmness indices obtained by this device for apple fruit were correlated more than 92% and 93% with puncture firmness and elasticity module respectively, and were significant at 1% level. Experimental results showed that the vibration signals have better results for estimation of elasticity modulus (more than 96 % accuracy) and acoustic signals to estimate the firmness (accuracy of more than 95 %).

The annually production of cattle manure is estimated around six million tons in Iran. Manure transportation with high moisture and low density recognized as crucial issue. The densification of dry or wet manure is the profound method for decreasing the manure volume which reduces the cost of handling and storage. Besides, the particle size is one of the important factors in the pellet production. Ball mills, vibratory mills, hammer mills, knife mills, two roll mills, colloid mills, attrition mills, or extruders can be used for size reduction of biomass. Specific energy consumption for size reduction of biomass highly depends on moisture content, bulk and particle densities, feed rate of the material, particle size distribution (initial/final particle size) and machine variables. The present study is conducted for wet cattle manure size reduction machine. Furthermore, the relationship between moisture content (35, 40 and 45 %w.b) and drum of special size reduction machine in rotational speed (150, 200 and 250 rpm) considering geometric mean diameter of particle and size distribution of wet cattle manure were investigated. A factorial experiment under randomized complete design method was employed with three replications.

The main parts of machine include drum, concave, spring and adjusting screw. The main function of this thresher machine is to combine crushing and cutting in order to conduct the size reduction methods, i.e., to apply compressive and shear forces to the cattle manure particles. The drum is also equipped with several rows of sharp-edged milling segments. The spring constants were determined by evaluating the slope of the force vs. deflection curves. The rotational speed of drum was changed in the range of 100-700 rpm during these experiments. In the test of the machine physical properties of grinds such as geometric mean diameter of grind particles and particle size distribution were determined. One kg of cattle manure was grinded in each test and the particle size distribution of grinded cattle manure was determined according to ASAE standard S319.3. The moisture content of cattle manure was obtained according to ASAE standard S358.3.

The initial and final particle size of the materials are 20 millimeters and less than 5 millimeters, respectively and the angle of nip is 30 degrees (according to the installation space limitations), the diameter of the drum is 310 millimeters. The spring constant was equal to 24.371 N / mm and on the basis of the experiments a drum speed in the range of 150–250 rpm is considered to be optimal settings for the milling for cattle manure disintegration. The results of Table 4 show that for wet cattle manure with 35% (w.b) moisture content at 250 rpm rotational speed of drum (P > 0.05; Skewness = -0.056; Kurtosis = -2.15), 40% (w.b) moisture content at 250 rpm rotational speed of drum (P > 0.05; Skewness = 0.076; Kurtosis = -1.77), 45% (w.b) moisture content at 200 rpm rotational speed of drum (P > 0.05; Skewness = 0.095; Kurtosis = -1.72), in grinds that would potentially produce better compacts. The geometric mean particle size and standard deviation for each test are shown in Table 2. According to Table (2), the lowest geometric mean of particle size is related to rotational speed of 200 rpm and a moisture content of 45% (w.b), and the highest at rotational speed of 250 rpm and a moisture content of 45% (w.b) can be observed.

The use of cattle manure of thresher machine reduces the specific energy consumption of cattle manure by 92% compared to the conventional method (using drying and hammer mill) in the pellet production.The lowest geometric mean diameter of wet cattle manure was 1.02 millimeter for drum rotational speed of 200 rpm at 45% (w.b) moisture content and the highest was 1.38 at rotational speed of 250 rpm and a moisture content of 45% (w.b%).The best particle size distribution was observed for milling of wet cattle manure with 35% (w.b) moisture content at 250 rpm rotational speed of drum (P> 0.05; Skewness = -0.056; Kurtosis = -2.15), 40% (w.b) moisture content at 250 rpm rotational speed of drum (P> 0.05; Skewness = 0.076; Kurtosis = -1.77), 45% (w.b) moisture content at 200 rpm rotational speed of drum (P> 0.05; Skewness = 0.095; Kurtosis = -1.72)

One of the methods of using livestock exhaust is compressing and pelletting it, which causes facilitation of transportation, reduction of odor and gradual release of nitrogen. For manure pelleting, extruder and disk pelleting are used. Since the stones existing materials in the stored manure cause damage to the pelletting apparatus, so the removal of the stone from the manure before the processing is necessary. In this research, with the aim of separation the rock from the manure, a gravity separator was designed and fabricated. The performance of the device was evaluated by changing the three slope parameters of the material separator plates, manure moisture content and the size of the stone and manure dimensions The changed level was for 10, 15 and 20 ° slopes of separators, 10, 30 and 50% of the moisture content of manure, and for the particle size of less than 10, 10 to 20 and 20 to 50 mm. The maximum device separation efficiency of the stone from the manure was 76.81% at 10 ° slope, 50% moisture content and a particle size less than 10 mm.

Application of traditional methods for the separation and sorting of healthy products from defective is a tedious and laborious, which needs fast and low cost non-destructive diagnostic system to overcome this problem. The present study was conducted with the aim of determining the internal quality of the tuber agricultural product (potato, Banba variety) with non-destructive sound test during the storage duration of 44 days with 78% moisture content. In order to determine the internal quality of the product during shelf life storage, sound and pressure test (as a control) were used. The results showed that the acoustic test has the ability to determine the quality of potato during the storage period. Also the effect of two independent variables of storage time and sample mass was compared on the bio-yield force (pressure test) and the firmness index using acoustic test. The results of this research revealed that the storage duration and mass of samples were significant at 1% probability level on quality parameters. In this study, the correlation coefficient between the firmness index and bio-yield force and the modulus of elasticity was 66% and 63%, respectively. The overal results of this research revealed sound test is capable for diagnostic internal quality of potato during 44 days of storage.

Today's energy consumption is increasing in developing countries. Most countries generate electricity from fossil fuels. Combined cycle plants produce 1 kg of 660 g of carbon dioxide gas. In study Firouzkouh province of Tehran province has been studied to use a small turbine to supply electricity to greenhouses. According to the study, Firuz Mountain has a wind density142 (w / m2) at a height of 10 meters from the ground. In this The wind speed is 5.6 m/s. Due to the wind speed and wind density in the Firoozkouh region, wind turbines of 10 and 5 kW have been used for further investigation. The 10 and 5 kW Hummer turbines produce 2394 and 1532 watts, respectively, with respect to the region's wind velocity, respectively. To reduce greenhouse costs, it is possible to invest in wind energy, while taking advantage of the environmental benefits of dispersed production and reducing the cost of greenhouse products in the long run. The reviews of this paper show that turbines 10 and 5 kilowatts of hammer in the Firoozkooh area and 10 meters high for installation and use.

Compression is one of the suitable solutions to reduce the volume of biomass materials. The cattle manure pellet production (extruder) transforms manure into pellet in the humidity range of 35 to 45 percent (based on the wet). The use of a size reduction machine is necessary for grinding cattle manure in pellet production.  The objective of this study was determining specific energy consumption for grindingwet cattle manure at three levels of moisture content of cow manure (35, 40 and 45 % w.b) and three levels of thrasher unit rotational speed (150, 200 and 250 rpm) using special size reduction machine. The experiment was a factorial arranged in a Randomized Complete Design with three replications. One Kg of cattle manure was grinded in each test and the particle size of grinded cattle manure was determined. The highest specific energy consumption was 4.62 (KJ / Kg) for thrasher unit rotational speed of 150 rpm at 45 % (w.b) moisture content. The thrasher unit rotational speed was negatively connected with specific energy consumption, such that in the highest rotational speed of thrasher unit (250 rpm), lowest specific energy consumption (1.72 KJ/Kg) was observed. The lowest geometric mean diameter of wet cattle manure was 1.02 for thrasher unit rotational speed of 200 rpm at 35% (w.b) moisture content.

Selecting the type of energy for electricity and power generation depends on the policies of the related country. Due to the adoption of stringent environmental laws and also because of the energy crisis, currently the development of renewable energies for countries especially industrial ones are paramount of significant. Iran is one of the largest producers and exporters of petroleum oil and natural gas in the world. Because of this, development of renewable energies did not attract considerable attention during the past decades. Though several researches were done by Iranian researchers to investigate the current status and prospects of renewable energies, very little literature has been found on the problems and limitations faced for renewable energy development. Therefore, the main purpose of this work in addition to report of the potential of renewable energies production in Iran such as wind energy, solar energy, hydropower energy, geothermal energy, biomass energy, biofuel energy and tidal and wave energies is to provide technical support and policy tools to address some barriers facing the development and utilization of renewable energies in Iran.

The Iran's share of global production of date palm was 1,157,000 tons. It could be estimated that 11000 tons of date pit oil can be extracted annually. The aim of this study was to investigate the effect of particle size, moisture content and the type of solvent parameters on oil extraction from Mazafati date pit and biodiesel production from that. The effect of particle size in two levels, the solvent type and moisture content parameters on three levels were investigated on oil extraction from Mazafati date pit. The extracted date pit oil converted to biodiesel by transesterification reaction. Ultrasound waves used in order to produce biodiesel. The ultrasound parameters were vibration pulse on three levels, ultrasound duration on two levels and fixed vibration amplitude at 60%. Some of the properties of produced biodiesel from date pit oil were determined. The results showed that the effects of moisture content, particle size, type of solvent and interaction effect of moisture content by solvent type were significant (P

In this study the effect of a hybrid muffler on sound emitted of a small gas generator which has been covered by an acoustic enclosure was investigated. The specifications of a reactive muffler were calculated according to the recommendation of ASHRAE 2.6 committee and appropriate muffler was selected. The selected muffler was added to the muffler installed by manufacturer on generator (GM) and formed hybrid muffler (HM). The sound of generator set was measured for GM and HM modes on four sides of the generator at five different loading conditions (0%, 25%, 50%, 75% and 100% load) using a sound level meter. The results showed that the application of HM could reduce the sound of generator at firing frequency (31.5 Hz) and frequencies greater than 1000 Hz, with the maximum values of 11.7 dB and 26 dB, respectively. The overall A-weighted generator sound was in the range of 73.2-85.8 dB(A) for all loading conditions and sides by using HM. The acoustical performance of HM on the side with the maximum generator sound (in front of the exhaust) increased from 5.1 dB(A) at no load to 10.61 dB(A) at full load conditions. Therefore, the HM usage could be recommended as a useful approach to attenuate the generator sound.

Cucumber fruit consumes in high quantities during all seasons in Iran; so it is important to evaluate parameters that affected the cucumber quality. Measurement of these parameters is expensive and time-consuming process. Therefore, parameters prediction due to affecting factors will be more useful. In this research work, artificial neural networks used for modelling the relationship between mechanical properties (crispness index and firmness) and sound pressure during cutting (acoustic response) with storage time, storage conditions on different positions on cucumber fruit. The networks input were storage time, storage conditions and test position on the fruit length. The networks output targets were the values of the mechanical properties and acoustic response. The different networks defined and trianed with different topologies. Multi layer perception (MLP) and radial basis function (RBF) networks used with different number of neurons. The training rules were Momentum, Conjugate Gradient and Levenberg-Marquardt. The transfer functions were TanhAxon and SigmoidAxon. The networks evaluated respected to estimation the accuracy of acoustic and mechanical properties. The results showed that MLP network with Momentom training function, TanhAxon transfer function and 3-5-3-3 topology had the best accuracy for prediction of acoustic and mechanical properties of Viola cucumber fruit. This network can predict the sound pressure, crispness index and firmness of the fruit with determinations coefficient of 0.9973, 0.9456 and 0.9129 and root mean square error of 0.021, 0.052 and 0.059 respectively.

One of the ways used for minimizing the cost of maintenance and repairs of rotating industrial equipment is condition monitoring using acoustic analysis. One of the most important problems which always have been under consideration in industrial equipment application is confidence possibility. Each dynamic, electrical, hydraulic or thermal system has certain characteristics which show the normal condition of the machine during function. Any changes of the characteristics can be a signal of a problem in the machine. The aim of condition monitoring is system condition determination using measurements of the signals of characteristics and using this information for system impairment prognostication. There are a lot of ways for condition monitoring of different systems, but sound analysis is accepted and used extensively as a method for condition investigation of rotating machines. The aim of this research is the design and construction of considered gearbox and using of obtaining data in frequency and time spectrum in order to analyze the sound and diagnosis.
This research was conducted at the department of mechanical biosystem workshop at Aboureihan College at Tehran University in February 15th.2015. In this research, in order to investigate the trend of diagnosis and gearbox condition, a system was designed and then constructed. The sound of correct and damaged gearbox was investigated by audiometer and stored in computer for data analysis. Sound measurement was done in three pinions speed of 749, 1050 and 1496 rpm and for correct gearboxes, damage of the fracture of a tooth and a tooth wear.
Gearbox design and construction: In order to conduct the research, a gearbox with simple gearwheels was designed according to current needs. Then mentioned gearbox and its accessories were modeled in CATIA V5-R20 software and then the system was constructed.
Gearbox is a machine that is used for mechanical power transition from a productive source of power to a consumer, for torque meeting and for rotating speed needed for the consumer. In fact, gearbox is an interfere between power source and power consumer which produces a flexible communication between power source and power consumer. Needing to a gearbox as a machine which can generate harmony as an interface is unavoidable due to lack of harmony of torque and rotating speed of production source of power. So necessary calculations in order to attain to technical characteristics of gearwheels, bearings, shaft dimensions and other accessories of gearbox were done. This gearbox is from kinds of simple gearwheel which its input and output shaft are parallel to each other.
Main accessories of gearbox are: 1.crust 2.shaft 3.gearwheel 4.thorn 5.bearing 6.cover. All of the design parameters were calculated and considered in designing of all of the accessories of gearbox.
Electromotor rotating calibration: For this aim, a light-contact telemeter in model of Lutron was used as contact.
Acoustic module of electro motor: A module was constructed in order to prevent from sound waves interaction resulting from an electromotor function with waves of gearbox function. Three layers of sound absorbent including common felt with 1mm width, polyethylene foam with 15 mm width and shoulder foam egg with 35 mm width were used for the module insulation. Material used for the body of this module was MDF. Based on field measurement, level of electromotor sound decrement using the acoustic module was 20dB. Investigated malfunctions in this research are relevant to gearwheel with one tooth fracture, one worn tooth and one tooth fracture and other worn tooth.
Collection and storage of acoustic data: In this research, an audiometer in model of HT-157 made in Italy in order to obtain acoustic data and a laptop with a model of Lenovo-G550 for data storage and processing was used. Cool Edit Pro 2.0 software was used for data processing. Data storage was in PCM format and MATLAB R2014a software used for data processing.
Data processing: Signal processing method in the frequency domain is used in order to reveal the defects.
Fast Fourier Transform: Fast Fourier Transform FFT for application in electronic equipment specially analyzers have great importance. In this condition, sampling number is chosen exponentially as 2N which decreases the calculation volume significantly.
Determination of defect kind of gearwheel using frequency spectrum analysis: In mentioned gearwheel, errors were generated synthetically. Defect kind of these errors was generated in separate gearwheels in order to investigate the defects more precisely and a gearwheel was considered as control gearwheel. Despite of this, the sound of all of the gearwheels in correct condition was stored.
Comparison of processed acoustic signals from gearwheels of gearbox in two correct and incorrect conditions was indicative of gearwheel involvement, frequency, their harmony and the changes resulted from defects. Gearwheel defect detection tests showed that at the speeds of 1496, 1050 and 749 rpm, investigated defects are recognizable with a comparison of the frequency spectrum of obtained signals in correct and incorrect conditions and according to the involvement frequency of gearwheel, its harmony and sided spectrum. Results of the frequency spectrum of signal analysis in speed of 1496 rpm pinion showed the defect of one tooth fracture in involvement frequency of gearwheels by 489, 350 and 249 Hz respectively which became apparent with a mentioned frequency domain increment. A worn tooth defect in a gearwheel was completely determinable as sided bands with equal distance around gearwheel involvement frequency in the signal frequency determination of the speeds of 1496 and 105 rpm pinion, but became a bit harder in less speeds. Investigation of frequency spectrum of acoustic signal resulted from gearwheel, is indicative of the ability of this method in gearbox condition investigation with high precision and minimum time. So the gearbox condition investigation is reached by investigation of the frequency spectrum of acoustic signal resulted from gearwheel.
In current research, acquisitive signals resulted from produced sound waves of constructed gearwheel were used for investigation and diagnosis. Recorded signal in time domain and processed frequency and exploited characteristics of signal in frequency domain for diagnosis were analyzed. Obtained results of this research can be summarized as follow: 1. Precision level in the diagnosis decreased by increasing in pinion speed.
2. There will be a decrement in gearwheel diagnosis after defects integration and signal behavior won’t be completely similar to the defect as individual.
3. Proper placement of audiometer is effective in diagnosis trend.
4. In frequency spectrum of obtained signals, particle velocity level is more efficient in diagnosis than the sound pressure level.

As a recently introduced method, entrance fuel magnetization, which is obtained from an external magnetic field, is a process through which exhaust gas emissions and fuel supply of internal combustion engines decrease. One of the preconditions of using the magnetized fuel in internal combustion engines is studying about the effects of fuel change on vibration behavior of the engines. Vibration of internal combustion engines can cause failure in engine components and agricultural machinery and vehicle’s drivers upset. In this research, diesel fuel in magnetic fields with different intensities of 1000, 2000, 3000 and 4000 Gauss was studied and Vibration signals of six-cylinder diesel engine (tractor MF-399) at five levels of engine speed and in the longitudinal, vertical and lateral directions were measured and recorded. The results show that the Root Mean Square (RMS) amounts of vibration acceleration were the most in the lateral direction and the least in the longitudinal direction (75.78 m/s2 and 44.59 m/s2 respectively). This research also shows that the RMS amounts of vibration acceleration decrease by increasing the magnetic field intensity and the lowest value of RMS belongs to a magnetic field intensity of 4000 Gauss.

In fluidized bed dryer, high velocity of air causes wastage of thermal energy. In order that fixed bed dryer be combined with fluidized bed dryer, it was mounted after fluidized bed in air way. According to the first law of thermodynamic, energy and effective parameters on energy consume were analyzed. Experiments were performed at three temperature ranges of, 60 and 70°C, three bed depths of 4, 6 and 8cm for the lower bed and two bed depths of 6 and 8 cm for the higher. Increasing bed depth of each bed showed clear effects on EU and EUR of the other floor. The EU value of top floor was more than that of bottom floor. Maximum energy consumption was obtained in 70 °C at 8dw-8up bed depth and energy consumption ratio was obtained in 50 °C at 8dw-8up.